Oxyalkylene compounds



I N Drawing.

OXYALKYLE Willard H. Kirkpatrick,

NE COMPOUNDS ugar Land, and Alice Walker,

Houston, Tex., assignors to Visco Products Company, Houston, Tex., a corporation of Delaware Original a Serial No. 271,978. Di tember 14, 1954, Serial pplication February 16, 1952, vided and this application Sep- 3 Claims. (Cl. zeta-Mas This invention relates to oityalkylene compounds, more particularly oxyalkylene and to a method for producing them. The invention is compounds containing silicon especially concerned with the preparation of organic silicon compounds in which connected to at least one alkylene chain.

The present application is a at least one silicon atom is high molecular weight oxydivision of copending application, Serial No. 271,978, filedFebruary 16, 1952, now U. S. Patent No. 2,790,777. 7

One of the objects of the vide a novel reagent which and Surface-active in order mulsifier or for such other present invention is to prois Water-Wettable, interfacial to. enable its use as a deuses where surface-active characteristics are necessary or desirable.

Another object of the i oil petroleum emulsions. inafter.

nvention is to provide compositions which are especially useful in breaking water-in- Other objects will appear here- The compositions prepared in accordance with this invention are high molecular weight organic silicon compounds in which a silicon atom is connected through an oxygen atom to a carbon atom forming a part of an ether alcohol, preferably an aliphatic ether polyol. The ether alcohol portion of the molecule consists essentially of oxyalkylene groups containing 1 each alkylene group and the major proportion of the molecular weight is preferably attributable to oxypropylene groups (e. g., oXy-l,2-propylene) or to mixed oxyethylene and oxypropylene groups in which the weight ratio of oxyethylene to oxypropylenedoes not exceed 4: 1..

The compositions falling vention can bederived in ing being illustrative:

( 1) An aliphatic ether alcohol can a silicon ester to produce Within the scope of the ina number of ways, the followbe condensed with a product having at least one terminal hydroxyl group connected to a polyoxyalkylene con ester group connected to chain and a terminal sili said chain.

(2) The product described in (1) can be further esterified by reacting the terminal hydroxyl group with a monobasic or a polybasic anhydride.

(3) Compositions in class organic carboxy acid or acid (1) can have free hydroxyl groups on the terminal silicon ester group.

(4) The products obtai ned under (3) can be further to 6 carbon atoms 'in' groups which are not polyamine the end product will be characterized by amine terminal groups.

(9) Where the condensation product has terminal carboxy acid groups it can be condensed further withamines to form amides.

(10) Where the condensation product has terminal carboxyacid groups such groups can be neutralized with ammonia, amines or alkalis to 'form salt groups.

It be seen from the foregoing discussion that the products prepared in accordance with. the invention are carboxylic acid amide groups. i

The followinggeneral formula illustrates one class of compounds :Which can be wherein R is alkyl, aryl or cycloalkyl; M is hydrogen, hydrocarbon or acyl; n is 2 to 6; z plus y equals 4; 2 can vary from 0 to 3; y can vary from 1 to 4, and x is at least 2; the valueof .2; preferably being such that the radical (C H OL has a molecular weight of at least condensed either with organic monocarboxy acids or polycarboxy organic acids or polycarboxy organic acid anhydrides.

(5) The condensation described under (1) can be effected to produce organic silicon compounds characterized by one or more oxysilane groups each connected to at least two polyoxyalk ylene chains.

(6) The aliphatic ether alcohol which is condensed (1) can have a terminal ether with a silicon ester as in group with the result that nal ether group connected a terminal silicon ester g the end product has a termito a polyoxyalkylene chain and roup connected to said chain.

H 020 OCi S H5020 OCgH This compound is also referred to as tetraethylorthosilicate." Instead of using a silane compound containing ethoxy groups it is also possible to use as a starting material a silane compound containing methoxy groups or higher alkoxy groups. Some of the alkoxy groups can also be replaced by alkyl ethyl, propyl, butyl, amyl, and higher homologues, or by aryloxy, cycloalkyloxy, aryl, or aralkyl groups.

In this formula the The compound which is reacted initially with the tetraethoxysilane or other alkoxysilane derivative should be a compound containing a polyoxyalkylene chain and having one .or more terminal hydroxyl groups. the compounds disclosed in United States 2,425,755, 2,425,845, characterized by an oxyalkylene chain and a terminal hydroxyl group can be employed for thisptupose'.

The invention is illustrated but is not limited by the 2,839,558 7 R Patented June 17, 1958 prepared in accordance with the invention: and are useful for breaking petroleum emulsions: 1

example, tetraeth-- groups, for example, methyl, 1

Patents 2,492,955 and 2,527,970 which are t.

following examples in which the quantities are stated in parts by weight unless otherwise indicated.

Example I In a reaction vessel equipped with thermometer, stirrer, and. means for refluxing a solvent with provisions for trapping any product which forms in the course of the reaction, there was mixed. 350 parts of-Ucon 25-1-1 Special and. 20 parts of condensed tetraethyl orthosilicate. The reactants were heated together with stirring at a temperature beginning at 160 C. and increasing to 240 C. After 4 hours of heating, approximately 11 parts of distillate hadbeen secured which was substantially ethanol resulting from the interchange of the ethyl radical. T o 100 parts offthis ester intermediate there was added 225 parts of a suitable'hydrocarbon fraction such as S0 extract to yield the finished product suitable for use as a demulsifying. agent.

Example 11 To 200 parts of the ester intermediate from Example I there was added 6 parts of phthalic anhydride and the reactants condensed for a period of 3 hours. The temperature range was maintained between. 220 C. and 295 C. A total of 11 parts of aqueous distillate was secured which indicatedthat the condensation had proceeded to the desired extent. To 100 parts of this reaction product there was added 225 parts of a suitable hydrocarbon fraction such as S0 extract to yield the finished product, which was suitable for use as a demulsifying agent.

Example III In equipment similar to that employed in Example I, 350 parts of Ucon 25-H Special and 30 parts of condensed tetraethyl orthosilicate were heated with agitation. 'At a temperature of 157 C. a distillate began to appear and after 4 hours and. a maximum temperature of 242 C. a total. of 16 parts of distillate had. been secured. This distillate was substantially ethanol indicating that ester interchange had occurred.

To 155 parts of the above intermediate there was added parts of maleic anhydride and 100 parts of a suitable hydrocarbon fraction such as S0 extract. Heating was applied to a maximum temperature of 160 C. for 1 hour. blended with 265 parts of a suitable hydrocarbonfraction such as S0 extract to yieldthe finished material suitable for use as a demulsifying agent.

Example IV The condensed reaction product was then densed tetraethyl orthosilicate were heated drastically with stirring. At a temperature of 160 C. a distillate began to appear. Heating was continued for 4 /2 hours at a maximum temperature of 243 C. with a yield of 32.5 parts of distillate. Toward the end of the heating considerable foaming and darkening of the product occurred.

To 300 parts of this intermediate there was added 30 parts of phthalic anhydride and 100 parts of a suitable hydrocarbon fraction such as S0 extract. The mass was heated for 4 hours at a temperature range of 163 C. to 189 C. There was no formation of distillate during this reaction. After cooling there was added to the mass 670 parts of a suitable hydrocarbon fraction such as S0 extract to yield the finished product suitable for use as a demulsifying, agent.

Example V In equipment similar to that employed in Example I, 600 parts of a polyoxypropylene glycol having a molecular weight of 2000, 19.2 parts of ethyltriethoxysilane and 100 parts of a suitable hydrocarbon fraction such as S0 extract were heated together with agitation until a 4- total of 13.8 parts of distillate were secured. This distillate was substantially ethanol and began to form at 200 C. and continued to a maximum temperature of 247 C.

To 140 parts of this intermediate there was added 5.2 parts of diglycolic acid and 50 parts of a suitable hydrocarbon fraction such as S0 extract. Heat was applied with agitation. At approximately 200 C. an aqueous distillate began to form and a total of 2 parts of aqueous distillate was secured after 6 hours at a. maximum temperature of 234 C. After cooling, 160 parts of a suitable hydrocarbon fraction such as S0 extract was added with stirring to yield the finished product suitable for use as a demulsifyiug agent.

Example Vl To 280 parts of the intermediate as prepared in Example V there was added 10 parts of maleic anhydride and parts of a suitable hydrocarbon fraction such as S0 extract. Heating was applied with agitation and the reaction product washeated between 148 and 158 C. for 5 hours. After cooling 340 parts of a suitable hydrocarbon fraction such as S0 extract was added with stirring to yield the finished product suitable for use as a dernulsifying agent.

, Example VII In equipment similar to that employed in Example I, 720 parts of Dow Polyglycol 15200, 19.2 parts of ethyltriethoxysilane and 100 parts of a suitable hydrocarbon fraction such as S0 extract were, heated with agitation. A total of 11.4 parts of distillate was secured between 191 C. and 227 C. over a period of 6 hours. This distillate was substantially. ethanol. The next day heating was continued and an additional 4.1 parts of distillate were secured at about 240 C. over a period of 2 hours. An additional 200 parts of a suitable hydrocarbon fraction such as S0 extract was added with stirring to yield this intermediate product.

To 200. parts of the diluted intermediate as above prepared there was added 20 parts of maleic anhydride and 50 parts of a suitable hydrocarbon fraction such as S0 extract. The mass was heated. for 5 hours at approximately 155 C. Upon cooling, 50 parts of methanol and 175 parts of asuitable hydrocarbon fraction such as S0 extract were added to yield the finished product suitable for use as a demulsifying agent.

Example VIII To 200 parts of the diluted intermediate from Example VII, there was added 13 parts of diglycolic acid and 100 parts of a suitable hydrocarbon fraction such as 50 extract. The mass was heated slowly with agitation and at 160 C. an aqueous distillate began to appear. After 5 hours additional heating and a maximum temperature of 225 C. there was a total of 3 parts of aqueous distillate formed. After coolingllO parts of a suitable hydrocarbon fraction such as S0 extract was added with stirring to yieldthe finished product suitable for use as a demulsifying agent.

0 Example IX In equipment similar to that employed in Example I, 245 parts of Ucon 75H150 and 150 parts of condensed tetraethyl orthosilicate were heated with stirring. Initially, the reaction mixture was very milky in appearance and at 118 C. the mass became much clearer and more homogeneous. At C. a distillate began to form. A very rapid reaction occurred at a temperature of C. to C. and a total of 95 parts of distillate was secured. At this stage the product was rubbery but was readily soluble in 150 parts of S0 extract.

To 200 parts of this diluted intermediate there were added 11 parts of maleic anhydride and 100 parts of a suitable hydrocarbon fraction such as S0 extract. The mass was condensed at C. for 2 hours. After cooling, 90 parts of the distillate secured from the preparation of the intermediate, consisting chiefly of ethanol, was added with stirring. To yield the finished material 200 parts of the above reaction product wereblended with 130 parts of a suitable hydrocarbon fraction such as S extract.

In the foregoing examples, Ucon 25-H Special is a polyoxyalkylene glycol having a molecular weight of approximately 2700 to 3500. The oxyalkylene groups consist of oxyethylene and oxypropylene radicals in a Weight ratio of oxyethylene to oxypropylene of 1:3. Dow Polyglycol 15-200 is a polyoxyalkylene triol cornposition in which the oxyalkylene groups consist of oxyethylene and oxypropylene in an equal molecular ratio. Ucon 75-H-150 is an addition product with diethylene glycol of ethylene oxide and 1,2-propylene oxide in a weight ratio of approximately 3:1 and having a molecular weight of approximately 35 As further illustrations of ether alcohols which can be employed in making condensation products in accordance with the invention there may be mentioned the following:

Approximate Average Molecular Weight Ucon 75-H-6000 6000 Ucon 75-H-90,000 90,000 Ucon 40-HDG-499 1375 Ucon 40-HDG-755 1850 Ucon 40-HDG-1026 2250 Ucon 40-HDG-1703 3100 Ucon 40-HDG-2412 3800 Ucon 25-HDG-510 1500 Ucon 25-HDG-876 A 2200 Ucon 25-HDG-1156 2600 Ucon 25-HDG-2157 4000 Ucon 10-HDG-373 1150 Ucon 10-HDG-506 .1600 Ucon 10-HDG-700 2100 Ucon 10-HDG-1682 3600 A polyoxypropylene glycol 750 A polyoxypropylene glycol 1025 A polyoxypropylene glycol 1525 A polyoxypropylene glycol 2000 Ucon -HB-660 1700 Ucon 50-HB-3520 3500 Ucon 50-HB-5100 5100 Ucon LB-625 1500 Ucon LB-l 145 1700 Ucon 50-1-ITD-76l 1635 Ucon 50-HTD-l294 2192 Ucon 50-HM-1277 2197 Ucon 50-HM-69l 1600 Ucon -HB-5100 5100 Dow Polyglycol 15-100 1000 Dow Polyglycol 19-120 1200 In the foregoing polyoxyalkylenc compounds the sym- 1301 H means that the compound contains both my ethylene and oxy-l,2-propylene groups. The symbol B stands for butyl. M represents methyl. 'TD represent tetradecyl. DG represents diethylene glycol. L means that the oxyalkylene groups are all oxy-l,2- propylene groups. The numerals in front of the letters indicate the percentage of ethylene oxide in the compound, the remaining percentage being 1,2-propylene oxide. The numerals after the letters indicate the viscosity Saybolt Universal Seconds at 100 F. For example, Ucon 50-HB-5100 is the monobutylether of a polyoxyalkylene glycol containing oxyethylene and oxy- 1,2-propylene groups in an approximate Weight ratio of 1:1; Ucon LB-1l45 is the monobutyl ether of a polyoxypropylene glycol; Ucon 40-HDG-499 is the addition product with diethylene glycol of ethylene oxide and 1,2-propylene oxide in a weight ratio of approximately 2:3; Ucon 25-HDG-2157 is the addition product with :weight ratio of oxyethylene to diethylene glycol of ethylene oxide and ij-prdp iese oxide in a weight ratio of approximately1r3; Ucon is theaddition product with diethylene glycol of ethylene oxide and 1,2-propylene oxide inla Weight ratio of approximately 1:9. Dow Polyglycol 15-100 and Dow Polyglycol 19-120 are both trihydroxy compounds. In the case of the Dow Polyglycol 15-100 the ethylene oxide and propylene oxide are in an equal molecular ratio. 'In Dow Polyglycol 19-120 the trihydroxy compound is built up with propylene oxide and ethylene oxide in a 2:1 ratio. In compounds containing both oxyethylene and oxy-1,2-propylene groups the 'oxy-l,2-propylene preferably should not exceed 4:1.

As illustrations of monovalent organic acids which may i be employed to introduce acyl groups into the end products there may be mentioned formic, acetic, propionic, butyric, abietic, trimethylhexanoic, tallol acids,-2-ethylhexanoic, lauric, stearic, trichloroacetic, oleic, ricinoleic, benzoic, phenyl acetic, anthranilic, naphthoic, toluene sulfonic, naphthalene sulfonic and petroleum sulfonic acids. As examples of polyvalent organic compounds which can be used to introduce acyl groups into the end product there may be mentioned succinic acid, malonic acid, adipic acid, phthalic acid, terephthalic acid, maleic acid, diglycolic acid and citric acid. Where these acids form anhydrides the anhydrides are the functional equivalents and, in most instances, are preferred over the acids.

The terminal ether groups on the end products can be, for example, methoxy, ethoxy, propyloxygoctyloxy, tetradecyloxy, .cetyloxy, myricyloxy and homologues thereof, preferably containing 1 to 30 carbon atoms. The terminal ether groups can also be oxycycloalkyl groups, for example, cyclopentyloxy, cyclohexyloxy and cycloheptyloxy. Alternatively, the terminal ether groups can be oxyaralkyl groups or oxyaryl groups.

In producing amino derivatives, typical specific examples of suitable monoamines are amylamine and diamylamine, cyclohexylamine and dicyclohexylamine, aniline and diphenyl amine, benzylamine and dibenzylamine,'

. dioctadecylamine, alpha-naphthylamine and beta-naphthylamine. Typical specific examples of suitable polyamines are ethylene diamine, propylene diamine, butylene diamine, decamethylene diamine, diethylene Itriaminc, triethylenetetramine, tetraethylenepentamine, diisopropylenetriarnine, triisopropylenetetramine, 0-, mand pphenylene diamine, benzidine andnaphthylenediamines.

I The preferred compositions are those in which the amine reactant is initially Water insoluble. The preferred compositions also are those in which the composition as a whole is aliphatic rather than aromatic.

Throughout the specification and claims the following definitions apply:

Alkyla monovalent radical derived from an aliphatic hydrocarbon by removal of one hydrogen atom, as, for example, methyl, ethyl, propyl, octyl, cetyl, myricyl and their homologues, preferably containing 1 to 30 carbon atoms;

Aralkyla monovalent radical derived from an aromatic substituted aliphatic hydrocarbon, as, for example, ben'zyl, phenylethyl, p'henylpropyl, phenylbutyl, phenyloctyl, phenylcetyl, phenyloctadecyl and homologues, preferably containing 1 to 30 carbon atoms in the alkyl chain;

Cycloalkyl-a monovalent radical derived from a cycloaliphatic hydrocarbon, as, for example, cyclopentyl, cyclohexyl and cycloheptyl;

Aryl-a monovalent radicalderived from an aromatic hydrocarbon by removal of one hydrogen atom, as, for example, phenyl and naphthyl;

$.Acyl-amonovalent radical derived from an organic -monoand, diglutamoyl, mono- .logues thereof, preferably containing r 7 acid by the removal of the hydroxy grou ,as,for-examp'le, formyl, acetyl, propionyl, butyryl, octoyl, lauryoyl, stearoyl, trichloroacetyl, oleyl, ricinoleyl, benZoyLphenylacetyl, naphthoyl, -monoand diphthaloyl, monoand dimaleoyl, monoand dimalonyl, monoand diadipoyl, and disuccinoyl, toluene sulfonyl, naphthalene sulfonyl and acylradicals derived from petroleum sulfonic acids;

Oxyalkyl-a monovalent radical derived' from an aliphatic alcohol by removal of the hydrogen atom of an alcoholic hydroxyl, as, for example, methoxy, ethoxy, propyloxy, octyloxy, cetyloxy, myricyloxy, and homo- 1 to 30. carbon atoms;

Oxyaralkyla monovalent radical derived from an aralkyl alcohol by removal of the hydrogen atom of an alcoholic hydroxyl, as, for example, -O-CH C H --O-C H C H oxypropylphenyl, o-xybutylphenyl, oxyoctylphenyl, oxycetylphenyl, oxyoctadecylphenyl, and homologues thereof, preferably containing 1 to 30 carbon atoms in the alkyl chain;

Oxyaryl-a monovalent radical derived from a phenol by removal of the hydrogen of thephenolic hydroxy, as, for examaple, phenoxy, naphthoxy, and homologues thereof;

Oxycycloalkyl-a monovalent radical derived from a cycloaliphatie alcohol by removal of the hydrogen of the alcoholic hydroxy, as, for example, cyclopentyloxy, cyclohexyloxy, cycloheptyloxy, and homologues;

Oxyacyla monovalent .radical having the structure represents an acyl group, as, for example, the formic acid ester, acetic acid ester, ricinoleic acid ester, diglycolic acid esters, phthalic acid esters, tallol esters, succinic acid esters, abietic acid ester, trimethylhexanoic acid ester, esters formed from alcoholysis products of castor oil, and homologues thereof;

Secondary amino-a monovalent radical derived by the removal of hydrogen from a nitrogen atom of a primary amine, as, for example, methylarnino, ethylamino, butylamino, and higher homologues;

Tertiary amino-a monovalent radical derived by the removal of hydrogen from a nitrogen atom of a secondary amine, as for example, dimethylamino, diethylamino, diisopropylamino, dibutylamino and higher homologues.

Especially good results have been obtained in the breaking of water-in-oil petroleum emulsions with the polyoxyalkylene polyol oxysilanes esterified with polycarboxy aromatic anhydrides, for example, phthalic anhydride and maleic anhydride, either in the form of their mono esters or as polyesters. The products of Examples I, i1, 111, IV and V merit special mention.

In general, in the preferred compositions of the invention themolecular weight of the composition attributable to the oxyalkylene groups is at least 1060 and preferably about 1500 to about 5000.

For breaking petroleum emulsions, the demulsifying compositions of the present invention are preferably employed in the proportions of one part of demulsifying agent to from 10,000 to 100,000 parts of emulsion either by adding the concentrated pro-duct directly to the emu1- sion or after diluting with a suitable vehicle in the customary manner.

Among the suitable hydrocarbon vehicles which can be employed as diluents is sulfur dioxide (S0 extract in which the products of the invention are soluble or dispersible. This material is a byproduct from the Edeleanu process of refining petroleum in which the undesirable fractions are removed by extraction with character remains which is extract, Examples of vehi cles are Gray Tower polymers, toluene, xylene, gas

liquid sulfur dioxide. After removal of the sulfur dioxide a mixture of, hydrocarbons, substantially aromatic in designated inthe trade as other, suitable hydrocarbon oil, diesel fuel, bunker fuel and coal tar solvents. The above,;cited ,examples of solvents are, adaptable to azeotropic distillation as would also be any other solvent which is imrniscible with water, miscible with the reacting groupsattached to said silicon atom being from the class consisting of hydrocarbyl and hydrocarbyloxy groups,

and the resultant compound being soluble in sulfur dioxide extract, the major portion of the molecular weight of the esters being attributable to oxyalkylene groups from the group consisting of oxy-1,2-propylene groups and both oxyethylene and oxy-1,2-propylene groups in a weight ratio of oxyethylene to oxy-1,2-propylene not exceeding 4:1.

2. An organic ester of a monocarboxylic organic acid and a polyoxyalkylene polyol oxysilane, there'being 1 to 6 carbon atoms in each oxyalkylene group of said ester and up to 4 polyoxyalkylene groups attached to each silicon atom, any group other than oxyalkylene groups attached to said silicon atom being from the class consisting of hydrocarbyl and hydrocarbyloxy groups, and the resultant compound being soluble in sulfur dioxide extract, the major portion of the molecular weight of the esters being attributable to oxyalkylene groups from the group consisting of oxy-1,2-propylene groups and both oxyethylene and oxy-l,2-propylene groups in a weight ratio of oxyethylene to oxy-1,2-propylene not exceeding 4:1.

3. An organic ester of a member from the group consisting of polycarboxylic organic acids and carboxylic acid anhydrides and a polyoxyalkylene polyol oxysilane, there being 1 to 6 carbon atoms in each oxyalkylene group of said ester and up to 4 polyoxyalkylene groups attached to each silicon atom, any group other than oxyalkylene groups attached to said silicon atom being from the class consisting of hydrocarbyl and hydrocarbyloxy groups, and the resultant compound being soluble in sulfur dioxide extract, the major portion of the molecular weight of the esters being attributable to oxyalkylene groups from the group consisting of oxy-1,2-propylene groups and both oxyethylene and oxy-1,2-propylene groups in a weight ratio of oxyethylene to oxy-1,2-propylene not exceeding 4: 1.

4. An organic ester of a member from the group consisting of dicarboxylic organic acids and carboxylic acid anhydrides and a polyoxyalkylene polyol oxysilane, there being 1 to 6 carbon atoms in each oxyalkylene group of said ester and up to 4 polyoxylkylene groups attached to each silicon atom, any group other than oxyalkylene groups attached to said silicon atom being from the class consisting of hydrocarbyl and hydrocarbyloxy groups, and the resultant compound being soluble in sulfur dioxide extract, the major portion of the molecular weight of the esters being attributable to oxyalkylene groups from the group consisting of oxy-l,2-propylene groups and both oxyethylene and oxy-1,2-propylene groups in a weight ratio of oxyethylene to oxy1,2-propylene not exceeding 4:1.

5. A polyester of a member from the group consisting of dicarboxylic organic acids and carboxylic acid anhydrides and a silicon ester of a polyoxyalkylene polyol having at least one free hydroxyl group, the oxyalkylene groups of said polyol being from the group consisting of oxy-1,2-propylene groups and both oxyethylene and oxyl,2-propylene groups in a weight ratio of oxyethylene to oxy-1,2-propylene not exceeding 4:1 and the molecular Weight of said polyester attributable to said oxyalkylene groups being at least 1500, any group other than oxyalkylene groups attached to silicon in said polyester be ing from the class consisting of hydrocarbyl and hydrocarbyloxy groups.

6. A polyester of phthalic anhydride and a silicon ester of a polyoxyalkylene polyol having at least one free hydroxyl group, the oxyalkylene groups of said polyol being from the group consisting of oXy-1,2-propylene groups and both oxyethylene and oxy-1,2-propylene groups in a Weight ratio of oxyethylene to oxy-1,2-propylene not exceeding 4:1 and the molecular weight of said polyester attributable to said oxyalkylene groups being at least 1500, any group other than oxyalkylene groups attached to silicon in said polyester being from the class consisting of hydrocarbyl and hydrocarbyloxy groups.

7. A polyester of maleic anhydride and a silicon ester of a polyoxyalkylene polyol having at least one free hydroxyl group, the oxyalkylene groups of said polyol being from the group consisting of oxy-1,2-propylene groups and both oxyethylene and oXy-1,2-propylene groups in a weight ratio of oxyethylene to oxy-1,2-propy1- ene not exceeding 4:1 and the molecular weight of said polyester attributable to said oxyalkylene groups being at least 1500, any group other than oxyalkylene groups attached to silicon in said polyester being from the class References Cited in the file of this patent UNITED STATES PATENTS 2,476,307 Klein et al. July 19, 1949 2,584,351 Hunter et al. Feb. 5, 1952 2,630,446 Gresham Mar. 3, 1953 

1. AN ORGANIC ESTER OF A MEMBER FROM THE GROUP CONSISTING OF CARBOXYLIC ORGANIC ACIDS AND CARBOXYLIC ACID ANHYDRIDES AND A POLYOXYALKYLENE POLYOL OXYSILANE, THERE BEING 1 TO 6 CARBON ATOMS IN EACH OXYALKYLENE GROUP OF SAID ESTER AND UP TO 4 POLYOXYALKYLENE GROUPS ATTACHED TO EACH SILICON ATOM, ANY GROUP OTHER THAN OXYALKYLENE GROUPS ATTACHED TO SAID SILICON ATOM BEING FROM THE CLASS CONSISTING OF HYDROCARBYL AND HYDROCARBYLOXY GROUPS, AND THE RESULTANT COMPOUND BEING SOLUBLE IN SULFUR DIOXIDE EXTRACT, THE MAJOR PORTION OF THE MOLECULAR WEIGHT OF THE ESTERS BEING ATTRIBUTABLE TO OXYALKYLENE GROUPS FROM THE GROUP CONSISTING OF OXY-1,2-PROPYLENE GROUPS AND BOTH OXYETHYLENE AND OXY-1,2-PROPYLENE GROUPS IN A WEIGHT RATIO OF OXYETHYLENE TO OXY-1,2-PROPYLENE NOT EXCEEDING 4:1. 